Personalization, based on information about the reader or the reader’s device, including location or history on the site.

Simplified search and other ways to speed one’s performance on the site, such as the ability to save articles for later access.

Ties to social media and communities, since mobile devices are, first and foremost, used to connect people.

Design consistency so that your mobile experience is part of the same family as your other products. Likewise, the design language and user experience should be appropriate for mobile.

Speed kills. Or rather, slowness does. Most mobile devices must contend with bandwidth constraints, as well as a broad spectrum of process speeds and battery power. (The more data you send to a phone, the faster its battery drains.) So, thoughtful publishers strive to streamline their sites and improve the experience for their users.